There are indications that Crocodylus moreletii and Crocodylus acutus are hybridizing in sympatric zones of Belize and Mexico in the Yucatan Peninsula, although the frequency and degree of genetic contact has yet to be established (Ray et al. 2004, Cedeño-Vázquez et al. in revision, Rodriguez et al. in revision).

Justification:
Although Crocodylus moreletii was heavily exploited during the early and mid 20th century, populations have recovered considerably, and healthy populations thrive throughout much of the species range, therefore this species has been assessed as Least Concern. Monitoring of this species should be carried out to ensure that any future population declines are noted.

This species is distributed from northeastern Mexico's central Tamaulipas area, through the Yucatan Peninsula to northern Guatemala and central Belize. From 2002 to 2004, Mexico developed the "COPAN" project to assess the presence of the species across its historical range and in outlying areas; 63 localities were surveyed in 10 States (Sigler and Dominguez 2008). In Mexico, C. moreletii occupies an estimated area of 396,455 km² (estimated by GARP algorithm and based on historical and actual localities). Total historical distribution across all three range states has been estimated as 450,000 km², of which 88% lies in Mexico (CONABIO 2006).

While this species has suffered population declines throughout its range, it is thought to be widely distributed in much of its original habitat (Ross 1995) and in protected areas there are healthy populations (Ross 1998). This species suffered severe population declines in the early 20th century due to exploitation (Casas-Andreu and Guzmán 1970) and was nearly extirpated in several portions of its range, however, after conservation action and legislative protection, many subpopulations are recovering (Platt and Thorbjarnarson 2000, Dominguez-Laso 2006). According to recent survey data, Domínguez-Laso (2006) estimated the population size to be between 79,000 and 100,000 individuals in Mexico. Available survey data for the three range states: Guatemala (Castañeda 2000), Mexico (CONABIO 2006) and Belize (Meerman pers. comm. in CONABIO 2006), suggest the relative abundance of C. moreletii is similar to other crocodilians that are not endangered. Morelet's Crocodile populations in Belize recovered rapidly following cessation of skin hunting, and the species is now regarded as common, even occurring within urban areas such as Belize City (Platt et al. 2008).

The species inhabits mainly freshwater areas such as marshes, swamps, ponds, rivers, lagoons and man-made waterbodies, but occasionally is found in brackish or saline habitats (Alvarez del Toro and Sigler 2001, Escobedo-Galvan et al. 2008, Platt et al. 2008). Females construct a mound nest of fresh and decomposing vegetation and soil, into which 20-50 eggs are laid at the end of the dry season (usually mid-May to late June or early July). Hatching occurs in August and September, when the wet season is at its peak, after approximately 75 to 85 days of incubation (Alvarez del Toro 1974, Perez-Higareda 1980, Platt et al. 2008).

Morelet's Crocodile is legally protected in the three range states. Legal trade in the species from Mexico is restricted to animals from CITES-registered captive breeding operations. Total annual production from the two CITES-registered farms (in 2009) was around 8,000 skins, with half going to local markets and the remainder being exported (CONABIO 2006). None of the three range states have established legal use of wild populations (CONABIO 2006). Mexico successfully downlisted C. moreletii populations in Mexico and Belize to CITES Appendix II, with a zero quota for commercial trade in wild specimens, at the 15th CITES meeting (March 2010). Although no use of the wild population is proposed at this time, it is a possible option in the future.

Populations of Morelet's Crocodile were greatly reduced in many areas due to unregulated skin hunting, which occurred principally in the 1940s and 1950s (Alvarez del Toro 1974, Platt and Thorbjarnarson 2000). A prohibition was decreed for the region in the 1970s, but illegal hunting persisted into the 1980s and 1990s. Due to severe sanctions, illegal hunting is now thought to be minimal, but still considered to be the principal threat to population recovery in some areas. Traditional use of the species persists, especially in rural communities (Merediz-Alonso 1999, Zamudio-Acedo 2002).

Tests on wild eggs of this species show that exposure to chemical pollutants including pesticides may be a significant threat to the long-term survival of some populations (Wu et al. 2000).

There are diverse, ongoing conservation measures in place for this species, including captive breeding programmes, protected areas and national and international legislative protection. Monitoring of this species should be carried out.

Merediz-Alonso, G. 1999. Ecology, sustainable use by local people, and conservation of Morelet's crocodile Crocodylus moreletii in Sian Ka'an Biosphere Reserve, Quintana Roo, Mexico. State University of New York.

Rainwater, T.R., Platt, S.G., and McMurry, S.T. 1998. A population study of Morelet's crocodile (Crocodylus moreletii) in the New River Watershed of northern Belize. The 14th Working Meeting of the IUCN-SSC Crocodile Specialist Group: Pp. 206-220 in Crocodiles. IUCN: Gland.